Any help that I could get here would be appreciated.
I've got an '01,4.7 4x4,auto,175k on the ticker and it is driving me nuts.It has always seemed to run warm,finally my wife was driving it up a mountain pass above Santa Barbara in Nov,severe overheat and it died.

Got it home,it had cooled off by then,so I cranked it to see how bad the problem was.Water out the tailpipe,but no really bad noises or vibrations.Seemed to be simply blown head gasket and possibly warped heads.Tore it down,diagnoses confirmed,got the parts,rebuilt heads and put it back together.I replaced the cam gears,chains,oil pump and guides.Everything was lined up,rotated the crank several times before I put the valve covers back on,everything came back up to zero.I put the rest of it back together,it cranked right over and started right up.I had a small oil leak out of the right cover,but no other problems except that it won't idle.

I get a random 553 (I think) code(misfire on X cylinder),but nothing else.Cold,it will start,high idle,then slowly drop to about 800rpm.Major stumble off idle to about 2000rpm,then it smooths out.After it warms up 5-8 mins,it surges to about 1000rpm from idle then slowly drops to 3-400rpm then dies.No codes,nothing indicating what is wrong.All new gaskets(tb,manifold),vacuum lines.After reading several threads here,I have checked all electrical and vacuum lines and all seem to be good.It seems like all the sensor errors manifest as the same symptoms (bad idle,runs rough,no accel,ect) and I have pretty much run out of things to replace.I am just dense enough to start replacing things thinking that "This will solve the problem",but it hasn't so far. At this point,new IAC,CPS,CKS,TPS,ECM and plugs.Battery is +/-6yo but fully charged.Normal readings on a vacuum gauge.
Anything else that I can check before I roll it into the street and set it off with about a pound of thermite?

Thanks for any help
Terry

 

Now have you load tested the battery or swapped in a known good one? I would recheck your grounds on the motor also.

 

do as adukart said and have the battery load tested, check all of the battery connections and grounds. You might want to clean the idle air control valve also.

 

Swapped in a good bat,1yo,no change.All grounds have been checked several times.

 

New IAC,the throttle body has been cleaned fully.

 

Battery temp sensor?

 

Also make some custom grounds straight to the battery from the motor, body, and frame.

 

Temp sensor is working correctly,grounds to both heads,block,chassis and frame,still no bueno.This is getting very irritating,but thank you very much for the help and suggestions.

 

I have a little bluetooth dongle ($20 on ebay) that plugs into the obdII port and then connects to my phone via an app called torque ($5) and lets me monitor all kinds of sensors and such. If you have something like that maybe you could see what's going on when it's acting up.

 

check the O2 sensors. Having all that hot water blast them could have screwed them up.